It is depend on your project goal, (eg. security, scheduling, etc.)
PySyft is an open-source federated learning library based on the deep learning library PyTorch. PySyft is intended to ensure private, secure deep learning across servers and agents using encrypted computation. Meanwhile, Tensorflow Federated is another open-source framework built on Google’s Tensorflow platform. In addition to enabling users to create their own algorithms, Tensorflow Federated allows users to simulate a number of included federated learning algorithms on their own models and data.
To the best of my knowledge, TFF only supports simple local simulations, there is currently no support for deploying to platforms such as Raspberry PI. On the other hand, PySyft support for deploying on Raspberry PI.
You can follow this link to learn how to setup PySyft on a Raspberry PI :